JP2581867B2 - Thickness deviation disturbance rejection control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic thickness control system for a rolling mill.

[0002]

2. Description of the Related Art In recent plate thickness control, for example, “Plasticity and Working” Vol. 16 no. 168 (1975-1) P. 25 to P. 31 and “Journal of the System Control Information Society” Vol. .5, P.147 ~ P.154,1989
And “Sheet rolling theory and practice” P.223 to P.256, etc., as shown in the automatic plate thickness deviation control system {hereinafter, AGC (Automatic
Gauge Control).

As a method for simultaneously reducing the skid mark and roll eccentricity, the inventors have disclosed a method disclosed in Japanese Patent Application No. 2-278519.
No. (JP-A-4-15709) .

[0004] The prior art will be described below with reference to the drawings.

FIG. 8 is a diagram showing a rolling system incorporating a conventional automatic in-board thickness deviation control system. In FIG. 8, 1 is a rolling mill, 2 is a rolled material, 3 is a rolling position detector,
Is a rolling load cell, 5 is a rolling mechanism, 6 is an automatic plate thickness deviation control system (I), and when the rolling mill 1 is rolling the rolled material 2, the automatic plate thickness deviation control system 6 A signal from the rolling load cell 4 and a signal from the rolling position detector 3 are input to output a rolling position control signal to the rolling mechanism 5.

A conventional AGC generally has an automatic in-board thickness deviation control system (I), and FIG. 9 shows a principle diagram thereof. FIG.
1 is a block diagram showing a principle diagram of a rolling system equipped with a conventional plate thickness deviation control system. In FIG. 9, M: Rolling machine rigidity coefficient [kgW / mm] Q: Rolled material plasticity coefficient [kgW / mm] Δu: Roll interval change amount [mm] ΔS: Rolling position deviation [mm] ΔP: Rolling load deviation [kgW ] G _R: transfer function [no unit of pressure mechanism] Delta] h: exit side thickness deviation [mm] [Delta] H: thickness at entrance side deviation [mm] [Delta] S _e: b - Le eccentricity [mm] [Delta] R _r: reduction Reference [mm] (For example, a monitor AGC that measures the thickness and controls the thickness)
The output of the control system of another system represented by the operation amount is the roll interval
The amount of change. ) I: Automatic plate thickness deviation control system (the chain line) C _1: transfer function. When using a signal representing the pressing position deviation (ΔS) 1, 0 if not using a signal representing the pressing position deviation ([Delta] S) [no unit] C _2: converting the rolling force deviation signal to thickness deviation signal transduction Function [mm / kgW] C ₃ : General transfer function [ No unit ], and by adding a specific transfer function to C ₁ , C ₂ , C ₃ , the conventional automatic plate thickness deviation control system in the plate can be obtained. Rolling system equipped. In addition, the deviation here refers to a deviation from a reference value.

In FIG. 9, a transfer function G ₁ from the entrance side thickness deviation (ΔH) to the exit side thickness deviation (Δh) and a transfer function from the roll eccentricity (ΔS _e ) to the exit side thickness deviation (Δh). G ₂
It is, W = Q / (M + Q) using _{··· (5), G 1 =} W · (1-M · G R · C 3 · C 2 + G R · C 3 · C 1) / (1- _{M · W · G R · C} 3 · C 2 + G R · C 3 · C 1) ··· (6) G 2 = (1-W) · (1 + G R · C 3 · C 1) / (1- _{M · W · G R · C} 3 · C 2 + G R · C 3 · C 1) is expressed as (7), for any _{C 1, C 2, C 3} , G 1 + G 2 = 1 (8) holds.

Therefore, the conventional AGC has a property that when one of the characteristics of G ₁ and G ₂ is determined, the other is automatically determined. Hereinafter, a conventional method for controlling the thickness of a steel sheet will be specifically described with reference to FIGS. 9, 10 and 11.

First, a Mill Modulus Control type A
A rolling system equipped with GC will be described. Mill M
In the case of the AGC of the odulus control type, in FIG. 9, a representative value of C ₁ = 0 (9) C ₂ = α / M (10) C ₃ = 1 (11) is adopted. Shall say. Specifically, this is shown in FIG. However, in FIG. 10, alpha: -: an (arbitrary real number alpha), when G _R is using a high-speed reduction mechanism such as a hydraulic pressure mechanism, T _1: Ju training factor [no unit] time constant [ sec] However, by using the _{T 1 «1, G R = 1} / (1 + T 1 · s) become (12). At this time, the transfer function G ₁ from the entrance side thickness deviation (ΔH) to the exit side thickness deviation (Δh) and the roll eccentricity (ΔS _e )
From the output side thickness deviation transfer function G ₂ to (Delta] h) is, G ₁ = W · _{[T 1 · s + (1-} α) ] / _{[T 1 · s + (1-} Wα) ] .. (13) G ₂ = (1−W) · (T ₁ · s + 1) / [T ₁ · s + (1−W · α)] (14)

Next, a rolling system equipped with a Gauge Meter type AGC will be described. That is, FIG.
In is defined as the case of adopting the _{C 1 = 1 ··· (15)} C 2 = α / M ··· (16) C 3 = G / s ··· (17) becomes the representative value. Specifically, this is shown in FIG. A rolling system equipped with an AGC of the Gauge Meter type generally has an automatic plate thickness deviation control system I, but a Mill Modulus Control type AGC.
Compare with the GC, the automatic plate thickness deviation control system I, C ₂ is the same function system is that the C ₁ is different. In the AGC of the Gauge Meter type, a signal (ΔS) indicating a rolling position deviation and a signal (ΔS) indicating a rolling load deviation are used.
P) using the following equation: Δh = Δs + (α / M) · ΔP (18) The output side thickness deviation signal (Δ
h) and provide feedback.

In FIG. 11, α: tuning factor [ no unit ] (0 ≦ α ≦ 1) s: Laplace operator [1 / sec] The Laplace operator is written as 1 / s. If

[0012]

(Equation 1)

[0013] It means to carry out. G: integration constant [1 / sec].

[0014] G _R is, in the case of using a high-speed reduction mechanism such as a hydraulic pressure mechanism, expressed as _{G R = 1 / (1 +} T 1 · s) ··· (19). Here, T ₁ : time constant [sec] and T ₁ <<< 1.

At this time, the transfer function G ₁ from the entrance side thickness deviation (ΔH) to the exit side thickness deviation (Δh) and the roll eccentricity (ΔS
side thickness deviation out _e) (transfer function G ₂ to Delta] h) is, G ₁ = W ^{_{[T 1 · s 2 + s +}} G (1-α) ] / ^{_{[T 1 · s 2 + s +}} G (1-α · W) ] it is a _{··· (20) G 2 = (} 1-W) (T 1 s 2 + s + G) / ^{_{[T 1 · s 2 + s +}} G (1-α · W) ] .. (21).

[0016]

However, the control method using the conventional automatic plate thickness deviation control system has the following problems in detail. First, in the hot rolling process, the change in plasticity coefficient (ΔQ [kgW / mm]), thickness deviation on the rolling mill entry side (ΔH [mm]), and roll eccentricity (ΔS _e [mm]), Has a great effect on the thickness deviation (Δh [mm]) on the exit side of the rolling mill.

The ΔQ of the resistance between the skids, mainly the deformation resistance in the longitudinal direction of the slab, which is generated because the skid that supports the slab in the heating furnace generates unevenness in temperature having a period equal to the distance between the skids in the longitudinal direction of the slab. A bias with an equal period, which induces large deviations in the exit strip thickness of the rolling mill. This is commonly referred to as a skid mark.

ΔH is the thickness deviation on the entry side of the rolling mill. In a rolling mill equipped in tandem, the thickness deviation caused by the skid mark (ΔQ) in the preceding rolling mill is reduced by the rolling in the next rolling mill. Is included in the entry side thickness deviation. Hereinafter, the entry side thickness deviation (ΔH) includes the skid mark
(ΔQ) is considered to be included.

ΔS _e is the backup load of the rolling mill.
Rolling load fluctuation caused by eccentricity of the roll due to the key groove of the bearing portion of the roll is a sheet thickness deviation caused by causing a rolling position deviation. It is called.

The skid mark is a disturbance of 0.2 Hz to 1.0 Hz, the roll eccentricity is a disturbance of 4.0 Hz to 10.0 Hz, and the frequency bands are close to each other.

In the case where the conventional automatic plate thickness deviation control system I is not used or the use method is inappropriate even if it is used, the horizontal axis is time [sec] and the vertical axis is plate thickness [mm]. Figure 15
As shown in the product thickness graph, a large thickness deviation of about 100 [μm] occurs.

In FIG. 15, a wave having a large period is caused by a deviation of the thickness of the entrance side such as a skid mark, and a wave having a small period is caused by roll eccentricity.

Even when the conventional automatic plate thickness deviation control system I is used, the horizontal axis is time [sec], and the vertical axis is plate thickness [m
m] as shown in the product thickness graph of FIG.
The thickness deviation is not reduced.

In order to remove a skid mark which is a disturbance of 0.2 [Hz] to 1.0 [Hz], in order to make 20 · LOG | G ₁ | in 0.2 [Hz] to 1.0 [Hz] as small as possible, s = 0.0
In [rad / sec], we usually want to design 20 · LOG | G ₁ | to be −∞ [dB], but it is extremely difficult to realize.

Here, LOG means common logarithm, and | G ₁ |
Means the absolute value of G _1. Therefore, if | G ₁ | becomes zero, 20 · LOG | G ₁ | becomes −∞ [dB].

Hereinafter, when the conventional control method is used, 20 ·
The reason why it is difficult to design LOG | G ₁ | to −∞ [dB] is as follows. The characteristics of 20 · LOG | G ₁ | and 20 · LOG | G ₂ | Take a logarithmic scale and plot the vertical axis as [d
12 and 13, and the product thickness graph when the conventional control method is used, the time [se
c] will be described in detail with reference to FIGS. 14 and 15 in which the ordinate represents the plate thickness [mm].

First, a Mill Modulus Control type AG
The case of C will be described.

When s = 0.0 [rad / sec], 20 · LOG | G
_{In order for 1} | to become -∞ [dB], the above-mentioned equation (13) G ₁ = W · [T ₁ · s + (1-α)] / [T ₁ · s + (1-Wα)] ·· (13) Accordingly, α = 1.0 is required (assuming that a high-speed reduction mechanism effective for reducing skid marks like a hydraulic reduction mechanism is used), but if α = 1.0, T ₁ ≪1.0 Therefore, as shown by the solid line in FIG. 12, not only the frequency band of the skid mark (0.2 [Hz] to 1.0 [Hz]), but also the frequency band of the roll eccentric disturbance (4.0 [Hz] to 10.0 [Hz]. Hz]), 20 · LOG | G ₁ | may be in the vicinity of −40 to −20 [dB], and from the relationship of the aforementioned equation (8), G ₁ + G ₂ = 1 (8) Naturally, it is difficult to reduce 20 · LOG | G ₂ | to −40 [dB] in the frequency band of roll eccentric disturbance (4.0 [Hz] to 10.0 [Hz]). Only the characteristics shown by the solid line are obtained.

As a result, an automatic plate thickness deviation control system
When I is used, as shown in FIG. 14, the roll eccentric disturbance (ΔS _e ) is markedly printed on the rolled material,
m].

Conversely, when the tuning factor α is set to 0.7 or 0.5, as shown in FIG. 15, the roll eccentricity has no effect on the exit side plate thickness deviation (Δh), but the low frequency Sukiddoma the G ₁ gain not completely reduced in frequency - thickness at entrance side deviations such as click ([Delta] H) remains in the rolled material,
A thickness deviation of about 100 [μm] occurs.

The characteristics of 20 · LOG | G ₁ | and 20 · LOG | G ₂ | indicated by dotted lines in FIGS. 12 and 13, respectively, are desirable.

Next, the case of the Gauge Meter type AGC will be described.

Also in this case, at s = 0.0 [rad / sec]
In order to make 20 · LOG | G ₁ | close to −∞ [dB], the above equation (20) G ₁ = W [T ₁ · s ² + s + G (1-α)] / [T ₁ · s ² + s + G (1−α · W)] (20) From the above, α = 1.0 is required (provided that a high-speed reduction mechanism effective for reducing skid marks like a hydraulic reduction mechanism is used). If α = 1.0, T ₁ ≪1.0, so as shown in the solid line in FIG. 12, not only the frequency band of the skid mark (0.2 [Hz] to 0.4 [Hz]) but also
Roll eccentric disturbance frequency band (4.0 [Hz] to 10.0 [H
z]), 20 · LOG | G ₁ | may be in the vicinity of −40 to −20 [dB], and from the relationship of the above equation (8) G ₁ + G ₂ = 1 (8) Inevitably, 20 · LOG | G ₂ | is -40 [dB] in the frequency band of roll eccentric disturbance (4.0 [Hz] to 10.0 [Hz]).
Is difficult to obtain, and only the characteristics shown by the solid line in FIG. 13 can be obtained. As a result, even using an automated plate thickness deviation control system I, b as shown in Figure 14 Figure - Le eccentricity disturbance ([Delta] S _e) is printed in significantly rolled material, as the 70 [[mu] m] This causes a thickness deviation.

Conversely, when the tuning factor α is set to 0.7 or 0.5, as shown in FIG. 15, the roll eccentricity has no effect on the exit side sheet thickness deviation (Δh), but it is low. Sukiddoma in frequency range without being completely reduced G ₁ gain - the remaining thickness at entrance side deviations such as click ([Delta] H) is a rolled material is 100 [[mu] m] as the the thickness deviation is caused.

In any case, the characteristics of 20 · LOG | G ₁ | and 20 · LOG | G ₂ | indicated by dotted lines in FIGS. 12 and 13, respectively, are desirable.

In other words, in the conventional plate thickness deviation control method, since there is only one automatic plate thickness deviation control system, 20 · LOG | G ₁ | at s = 0.0 [rad / sec] is obtained. −
When the tuning factor α approaches 1.0 in order to obtain ∞ [dB], 20 · LOG | G ₂ | is increased, and roll eccentricity (ΔS _e ) is promoted on the rolled material. On the contrary, when the tuning factor α is set to 0.7 or 0.5, etc., the roll thickness deviation (Δh)
In this case, there is no effect on the skid mark. However, in the frequency band of the skid mark (0.2 [Hz] to 1.0 [Hz]), 20 · LOG | G ₁ |
H) remains in the rolled material.

[0037] As described above, in the conventional plate thickness deviation control method, Sukiddoma - when you try to remove the entry side thickness deviation, such as click ([Delta] H), b - will not be able to Le eccentric ([Delta] S _e) is removed, Russia - If you try to remove the Le eccentricity (ΔS _e),
The entry side thickness deviation (.DELTA.H) such as a skid mark cannot be removed.

The control method of the present invention, b - removing Le eccentricity ([Delta] S _e), and, b - at the same time removing the Le and eccentricity ([Delta] S _e) and thickness at entrance side deviations ([Delta] H), for An object of the present invention is to provide a thickness deviation disturbance elimination control method.

[0039]

The method of the present invention has the following features.

During rolling of a steel sheet, a rolling load deviation ΔP [kgW] which is a difference between a rolling load reference value and a value measured by a rolling load cell.
And a roll position deviation ΔS [mm], which is a difference between a roll position reference value and a value measured by the roll position detector, and a roll gap change amount Δu [mm] as an output to control the thickness of the steel sheet. In the deviation disturbance elimination control method, the rolling load deviation,
Rolling position deviation, rolling mill rigidity coefficient M [kgw / mm], tube
Ning factor α [unitless] and reduction filter H
(S), where s [1 / sec] is the Laplace operator,
By F ₁ = [ΔS + (α / M) · ΔP] · H (s),
At the same time as calculating ΔF ₁ [mm], ΔF ₂ = − [ΔS
+ (Α / M) · ΔP] to calculate ΔF ₂ [mm],
A roll thickness change disturbance removal control method characterized in that a roll gap change amount is calculated by Δu = −ΔF ₁ −ΔF ₂ , wherein preferably, the low-pass filter H (s) is H (s) =
(Q · ω _n ² · α) / [M · s ² + 2 · M · η · ω _n · s + Q (α−
1) · ω _n ² ] where ω _n [rad / s] is the natural angular frequency and η
[Non-unit] is a damping coefficient, and Q [kgw / mm] is a rolling material plasticity coefficient.

[0041]

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram for explaining the principle of the thickness disturbance control method according to the present invention. In FIG. 1, the present invention has an automatic board thickness deviation control system I (within a dashed line) and an automatic board thickness deviation control system II (with a dashed line). In FIG. 1, C ₁₁ : transfer function. When the signal representing the rolling position deviation (ΔS) is used, 1 when the signal representing the rolling position deviation (ΔS) is not used, 0 [ no unit ] C ₁₂ : Transfer function for converting the rolling load deviation signal into a sheet thickness deviation signal [Mm / kgW] C ₁₃ : General transfer function [ no unit ] C ₂₁ : Transfer function. When a signal representing the rolling position deviation (ΔS) is used, 1 when a signal representing the rolling position deviation (ΔS) is not used, 0 [ no unit ] C ₂₂ : Transfer function for converting a rolling load deviation signal into a sheet thickness deviation signal [Mm / kgW] C ₂₃ : General transfer function [ No unit ] ΔF ₁ : Output of automatic plate thickness deviation control system I [mm] ΔF ₂ : Output of automatic plate thickness deviation control system II [mm] It is.

The method of the present invention is provided with an automatic inner plate thickness deviation control system I and an automatic inner plate thickness deviation control system II shown in FIG. LOG | G ₁ | in the frequency band of 0.2 [Hz] to 1.0 [Hz] is reduced to near -40 to -20 [dB], and the frequency of 4.0 [Hz] to 10.0 [Hz] is reduced. 20 ・ LOG in band |
By reducing G ₂ | to near -40 [dB],
It ensures that the skid mark disturbance and the roll eccentric disturbance are reduced at the same time.

20 in a frequency band of 0.2 [Hz] to 1.0 [Hz]
・ Reduce LOG | G ₁ | to close to -40 [dB], 4.0 [Hz]-
20 · LOG | G ₂ | in the 10.0 [Hz] frequency band is -40 [d
B] In order to reduce it to near, 20 ・ LOG | G ₁ |
The characteristics shown _{in, 20 · LOG | G 2 |} C ij as the characteristics shown in FIG. 4 is applied to the (i = 1~2, j =
1-3) The _{C 21 = 1 ··· (26)} C 22 = α / M ··· (27) C 23 = -1 ··· (28) C 11 = 1 ··· (29) C 12 = Α / M (30) C ₁₃ = (Q · ω _n ² · α) / [M · s ² + 2 · M · η · ω _n · s + Q (α−1) · ω _n ² ] ···・ Give as (31).

Further, G _R in the case of using the high-speed reduction mechanism such as a hydraulic pressure mechanism, expressed as _{G R = 1 / (1 +} T 1 · s) ··· (32). However, T ₁ : Time constant of the reduction mechanism [sec] s: Laplace operator [1 / sec] When Laplace operator is written as 1 / s,

[0046]

(Equation 2)

Means to execute.

Hereinafter, C _ij (i = 1 to 2, j = 1 to 3)
Is given in detail as in equations (26) to (31).

First, in FIG. 2, the entry side sheet thickness deviation (Δ
Transfer characteristic G ₁ and b from H) leaving the side thickness deviation (Delta] h) -
In calculating the transfer characteristic G ₂ to exit side thickness deviation (Delta] h) from Le eccentricity ([Delta] S _e), thickness at entrance side deviations of FIG. 1 (delta
Transfer characteristic G ₁ and b from H) leaving the side thickness deviation (Delta] h) -
After calculating the transfer characteristic G ₂ to side thickness deviation (Delta] h) out of the Le eccentricity ([Delta] S _e), (26) formulas (32) to C _ij (i
= 1~2, j = 1~3) and decided to specifically substituted for G _R.

In FIG. 1, the transfer characteristics G ₁ from the entrance side thickness deviation (ΔH) to the exit side thickness deviation (Δh) are W, M, G
_R and C _ij (i = 1 to 2, j = 1 to 3). This is shown in equation (33).

G ₁ = W [1−M · G _R · (C ₁₃ · C ₁₂ + C ₂₃ · C ₂₂ ) + G _R · (C ₁₃ · C ₁₁ + C ₂₃ · C ₂₁ )] / [1−W · M _{· G R · (C 13 ·} C 12 + C 23 · C 22) + _{[G R · (C 13 · C} 11 + C 23 · C 21) ] ... (33) Moreover, Russia - Le eccentric ([Delta] S _e ) transfer characteristic G ₂ to side thickness deviation (Delta] h) out _{is, W, M, G R,} C ij (i = 1~
2, j = 1 to 3). This is shown in equation (34).

[0052] _{G 2 = (1-W)} · _{[1 + G R · (C 13} · C 11 + C 23 · C 21) ] / _{[1-W · M · G R} · (C 13 · C 12 + C 23 · C ₂₂ ) + G _R · (C ₁₃ · C ₁₁ + C ₂₃ · C ₂₁ )] (34) Therefore, in FIG. 2, the transfer function G from the inlet side thickness deviation (ΔH) to the outlet side thickness deviation (Δh) is obtained. ₁ and roll eccentricity (Δ
The transfer function G ₂ from S _e ) to the exit side plate thickness deviation (Δh) is obtained by substituting the equations (26) to (32) into the equations (33) and (34), respectively, and T ₁ is the rolling-down mechanism. a time constant of, considering that when using a hydraulic pressure mechanism, etc. is T ₁ ≒ 0 (i.e. _{G R ≒ 1), G 1} = (s 2 +2 · η · ω n · s) / ( s ² + 2 · η · ω _n · s + ω _n ² ) (35) G ₂ = (ω _n ² ) / (s ² + 2 · η · ω _n · s + ω _n ² ) (36) be able to.

Based on this, 20 · LOG | G ₁ |, 20 · LOG | G ₂ |
The horizontal axis is [rad / sec], the logarithmic scale is used, and the vertical axis is [dB].
It can be understood that the characteristic graphs shown in FIGS. 3 and 4 are obtained.

According to the automatic two-degree-of-freedom plate thickness deviation control system of the present invention, 20 · L in a frequency band of 0.2 [Hz] to 1.0 [Hz] is used.
OG | G ₁ | is reduced to near -40 [dB], and from 4.0 [Hz] to 1
20 · LOG | G ₂ | in the 0.0 [Hz] frequency band is also -40
By reducing to near [dB], the skid mark disturbance and the roll eccentric disturbance can be reduced at the same time, and the thickness deviation can be reduced to 1/2 or less of the conventional thickness deviation.

[0055]

[Example] As an example, the specifications of a hot rolling mill and a steel sheet are as follows: M = 500,000 [kgW / mm] (37) Q = 2,000,000 [kgW / mm] (38) T ₁ = 1/240 [sec / rad] (39) This system was adopted in the case of α = 1 [ no unit ] (40).

The input side thickness deviation disturbance (ΔH) is 0.2 [Hz].
In the band of ~ 0.4 [Hz], roll eccentric disturbance is 4.0 [Hz]
Since the band to 10.0 [Hz], the frequency that separates the two considered 0.55 [Hz] (3.5 [rad / sec]), the angular velocity _{ω n, ω n = 3.5 [} rad / sec] ··· ( 41)

At this time, as shown in FIG.
20 · LOG | G ₁ | is reduced in the band of up to 0.4 [Hz], and as shown in FIG. 6, 20 · LOG | G ₂ | is reduced in the band of 4.0 [Hz] to 10.0 [Hz]. According to the embodiment, the skid mark disturbance in the band of 0.2 [Hz] to 0.4 [Hz] and the roll eccentric disturbance in the band of 4.0 [Hz] to 10.0 [Hz] can be simultaneously removed. Guaranteed.

Hereinafter, specific examples will be described.

Rolling load deviation: ΔP = 40,000 [KgW] (42) Rolling position deviation: ΔS = 0.0700 [mm] (43) from time 0.0 seconds to 0.1 seconds, and rolling reduction: ΔR _r = 0.0300 [mm] ... (44) After 0.1 seconds, the output of the automatic in-board thickness deviation control system I: ΔF ₁ = [0.0700 + {(1.0) / (500,000)} × 40,000] × 0.8 = 0.12 (45) Output of the automatic plate thickness deviation control system II: ΔF ₂ = (-1) × [0.0700 + {(1.0) / (500,000)} × 40,000] = − 0.15 (46) where (Q · ω _n ² · α) / [M · s ² + 2 · M · η · ω _n · s + Q (α−1) · ω _n ² ] = 0.8 ·・ ・ (47)

Accordingly, the roll gap change amount (Δu [mm])
Is Δu = 0.03−0.12 − (− 0.15) = 0.06
(48) is sent to the screw-down mechanism.

As shown in FIG. 7, the deviation of the product thickness is 50%.
[Μm] or less, which is about 1/2 or less of the thickness deviation (about 100 [μm]) according to the conventional method shown in FIG.

[0062]

With the introduction of the automatic two-degree-of-freedom inner plate thickness control system of the present invention, (1) a relatively close input side thickness deviation disturbance and a roll eccentric disturbance can be simultaneously eliminated; Accuracy can be improved, and (3) product yield can be improved,
be able to.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an automatic in-board thickness deviation control system that implements the present invention in one aspect.

FIG. 2 is a block diagram showing processing contents of components shown in FIG. 1;

FIG. 3 is a graph showing a change characteristic of a gain according to the embodiment of the present invention, and shows a graph of 20 · LOG | G ₁ |.

FIG. 4 is a graph showing a change characteristic of a gain according to the embodiment of the present invention, that is, 20 · LOG│G ₂ │.

FIG. 5 is a graph showing a change characteristic of a gain according to the embodiment of the present invention, showing a graph of 20 · LOG│G ₁ │.

FIG. 6 is a graph showing a gain change characteristic according to the embodiment of the present invention, showing a gain of 20 · LOG | G ₂ |.

FIG. 7 is a graph showing a product plate thickness according to an embodiment of the present invention.

FIG. 8 is a block diagram showing a conventional rolling system.

9 is a conventional automatic plate thickness deviation control system 6 shown in FIG.
FIG. 2 is a block diagram showing the configuration of I in blocks I.

FIG. 10 is a block diagram showing an example of specific setting values in each block in a block I shown in FIG. 9;

FIG. 11 is a block diagram showing another example of specific setting values in each block in block I shown in FIG. 9;

FIG. 12 is a graph showing a change characteristic of a gain by a conventional method, that is, 20 · LOG│G ₁ │.

FIG. 13 is a graph showing a gain change characteristic according to a conventional method, which is 20 · LOG | G ₂ |.

FIG. 14 is a graph showing a product plate thickness according to one conventional method.

FIG. 15 is a graph showing a product plate thickness according to another conventional method.

[Description of Signs] 1: Rolling machine 2: Rolled material 3: Rolling position detector 4: Rolling load cell 5: Rolling down mechanism 6, I, II: Automatic plate thickness deviation control system

Claims (2)

(57) [Claims] 1. A rolling load deviation ΔP [kgW] which is a difference between a rolling load reference value and a value measured by a rolling load meter during rolling of a steel sheet.
And a roll position deviation ΔS [mm], which is a difference between a roll position reference value and a value measured by the roll position detector, and a roll gap change amount Δu [mm] as an output to control the thickness of the steel sheet. In the deviation disturbance elimination control method, the rolling load deviation,
Rolling position deviation, rolling mill rigidity coefficient M [kgw / mm], tube
Ning factor α [unitless] and reduction filter H
(S), where s [1 / sec] is the Laplace operator,
By F ₁ = [ΔS + (α / M) · ΔP] · H (s),
At the same time as calculating ΔF ₁ [mm], ΔF ₂ = − [ΔS
+ (Α / M) · ΔP] to calculate ΔF ₂ [mm],
A control method for removing disturbance of thickness deviation, wherein a roll gap change amount is calculated by Δu = −ΔF ₁ −ΔF ₂ . 2. The low-pass filter H (s) is H (s) = (Q · ω)
_n ² · α) / [M · s ² + 2 · M · η · ω _n · s + Q (α-1) · ω _n
^2. The plate according to claim 1, wherein ω _n [rad / s] is a natural angular frequency, η [unitless] is a damping coefficient, and Q [kgw / mm] is a rolled material plasticity coefficient. Thickness deviation disturbance removal control method.